The invention relates to a trailer coupling for motor vehicles, including a cross member, which is connectable to a motor vehicle body, and a bearing unit, which carries a ball neck that at a first end is connected to the bearing unit and at a second end carries a coupling ball, and a holding base, which carries the bearing unit and is connected to the cross member.
Trailer couplings of this kind are known from the prior art, for example EP 2 261 066.
These trailer couplings have the problem that the holding base is to be produced with as much stability and at as low a cost as possible.